The mi in front of the root tzavoh, command, makes it passive, a “good work” or “love offering,” but not commanded. However, metzaveh is active, a real command. God commanded us, “All the commandment [kol ha-mitzvah] which I command [anokhi metzaveh] you this day you shall be careful to do” Deut 8:1.
The Catholic Church understands God’s law the same way. A single unrepented mortal sin can send us to hell for all eternity § 1857. Our first parents committed only one mortal sin Gen 3:6, and were driven out of paradise Gen 3:24. The Catechism of the Catholic Church, in its Glossary, states under Punishment, Eternal, “The penalty for unrepented mortal sin, separating the sinner from communion with God for all eternity; the condemnation of the unrepentant sinner to hell” p. 896.
Behold, the days are coming, says the Lord, when I will make a new covenant with the house of Israel and the house of Judah, not like the covenant which I made with their fathers when I took them by the hand to bring them out of the land of Egypt, my covenant which they broke, though I was their husband, says the Lord. But this is the covenant which I will make with the house of Israel after those days, says the Lord: I will put my law within them, and I will write it upon their hearts; and I will be their God, and they shall be my people Jer 31:31–33.